Source code for bokeh.colors.rgb

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# Copyright (c) 2012 - 2021, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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'''

'''

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# Boilerplate
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from __future__ import annotations

import logging # isort:skip
log = logging.getLogger(__name__)

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# Imports
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# Standard library imports
import colorsys
from math import sqrt
from typing import TYPE_CHECKING

# Bokeh imports
from .color import Color

if TYPE_CHECKING:
    from .hsl import HSL

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# Globals and constants
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__all__ = (
    'RGB',
)

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# General API
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[docs]class RGB(Color): ''' Represent colors by specifying their Red, Green, and Blue channels. Alpha values may also optionally be provided. Otherwise, alpha values default to 1. '''
[docs] def __init__(self, r: int, g: int, b: int, a: float = 1.0) -> None: ''' Args: r (int) : The value for the red channel in [0, 255] g (int) : The value for the green channel in [0, 255] b (int) : The value for the blue channel in [0, 255] a (float, optional) : An alpha value for this color in [0, 1] (default: 1.0) ''' self.r = r self.g = g self.b = b self.a = a
[docs] def copy(self) -> RGB: ''' Return a copy of this color value. Returns: :class:`~bokeh.colors.rgb.RGB` ''' return RGB(self.r, self.g, self.b, self.a)
[docs] @classmethod def from_hsl(cls, value: HSL) -> RGB: ''' Create an RGB color from an HSL color value. Args: value (HSL) : The HSL color to convert. Returns: :class:`~bokeh.colors.rgb.RGB` ''' return value.to_rgb()
[docs] @classmethod def from_rgb(cls, value: RGB) -> RGB: ''' Copy an RGB color from another RGB color value. Args: value (:class:`~bokeh.colors.rgb.RGB`) : The RGB color to copy. Returns: :class:`~bokeh.colors.rgb.RGB` ''' return value.copy()
[docs] def to_css(self) -> str: ''' Generate the CSS representation of this RGB color. Returns: str, ``"rgb(...)"`` or ``"rgba(...)"`` ''' if self.a == 1.0: return f"rgb({self.r}, {self.g}, {self.b})" else: return f"rgba({self.r}, {self.g}, {self.b}, {self.a})"
[docs] def to_hex(self) -> str: ''' Return a hex color string for this RGB color. Any alpha value on this color is discarded, only hex color strings for the RGB components are returned. Returns: str, ``"#RRGGBB"`` ''' return "#%02X%02X%02X" % (self.r, self.g, self.b)
[docs] def to_hsl(self) -> HSL: ''' Return a corresponding HSL color for this RGB color. Returns: :class:`~bokeh.colors.hsl.HSL` ''' from .hsl import HSL # prevent circular import h, l, s = colorsys.rgb_to_hls(float(self.r)/255, float(self.g)/255, float(self.b)/255) return HSL(round(h*360), s, l, self.a)
[docs] def to_rgb(self) -> RGB: ''' Return a RGB copy for this RGB color. Returns: :class:`~bokeh.colors.rgb.RGB` ''' return self.copy()
@property def brightness(self) -> float: """ Perceived brightness of a color in [0, 1] range. """ # http://alienryderflex.com/hsp.html r, g, b = self.r, self.g, self.b return sqrt(0.299*r**2 + 0.587*g**2 + 0.114*b**2)/255
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